Solve for $x$ and $y$ using elimination. ${x-4y = -11}$ ${-x+5y = 15}$
Answer: We can eliminate $x$ by adding the equations together when the $x$ coefficients have opposite signs. Add the equations together. Notice that the terms $x$ and $-x$ cancel out. ${y = 4}$ Now that you know ${y = 4}$ , plug it back into $\thinspace {x-4y = -11}\thinspace$ to find $x$ ${x - 4}{(4)}{= -11}$ $x-16 = -11$ $x-16{+16} = -11{+16}$ ${x = 5}$ You can also plug ${y = 4}$ into $\thinspace {-x+5y = 15}\thinspace$ and get the same answer for $x$ : ${-x + 5}{(4)}{= 15}$ ${x = 5}$